First Japanese record of the Freckleface Reef-eel Uropterygius xanthopterus from Kakeroma-jima island, Japan

Abstract

Uropterygius Rüppell, 1838 (Muraenidae) currently includes 21 valid species, six (one unidentified) having been recorded from Japanese waters, mostly off the Pacific coast of southern Japan to the Ryukyu Archipelago. The genus is characterized by a moderately elongate, laterally compressed body, the median fins restricted to the tail tip, and a small, slit-like gill opening. A single specimen (158.7 mm total length) of U. xanthopterus Bleeker, 1859 collected from Kakeroma-jima island, Amami Islands, Japan, was newly identified in museum collections, being characterized by 119 vertebrae, two lateral-line pores, and a dark brown body with three rows of stellate whitish to pale grey blotches, pale dots anteriorly and on the head, and a bright yellow tail tip. Previously known from the Maldives and Chagos Archipelagos to Micronesia and French Polynesia, and north to Taiwan, U. xanthopterus is recorded from Japan for the first time, the Amami Islands specimen being the northernmost known record. The new standard Japanese name “Kakeroma-kikaiutsubo” is proposed for the species.